German Published Patent Appln. No. 10 2005 020 380 describes a fuel injection device, which is characterized by a noise-decoupling construction. The known fuel injection device includes a fuel injector, a receiving bore for the fuel injector in a cylinder head and a fuel distributor line having a connection fitting, into which the fuel injector is inserted in a partially overlapping manner. In one possible development, a slotted snap ring is provided, which engages into a tapered section of an inflow fitting of the fuel injector. For this purpose a groove is furthermore provided in the connection fitting, in which the snap ring is engaged securely and firmly. For engaging below the fuel injector, the snap ring has a conical or vaulted spherical contact surface. A holding-down clamp is furthermore clamped between an end face of the connection fitting and a shoulder on the fuel injector.
The development of the fuel injection device known from German Published Patent Appln. No. 10 2005 020 380 has the disadvantage that vibrations may be transmitted from the fuel injector to the connection fitting via the snap ring. Furthermore, a sufficiently high retaining force must be applied via the holding-down clamp, which on the one hand holds down the fuel injector and on the other hand also applies a sufficient force on the fuel injector against the snap ring.
Especially in the case of electromagnetic high-pressure fuel injectors, which may be used in Otto engines having direct injection, an obtrusive and disturbing contribution to the overall noise of the engine may occur, which may be described as valve ticking. Such valve ticking arises from the rapid opening and closing of the fuel injector, in which the valve needle is displaced in a highly dynamic way to the respective end stops. The impact of the valve needle on the end stops leads to brief but very high contact forces which are transferred via a housing of the fuel injector to the cylinder head and to a fuel distributor rail in the form of structure-borne noise and vibrations. This leads to a strong noise development at the cylinder head and at the fuel distributor rail.